CN111836744B

CN111836744B - Condensate reduction system for a sensor

Info

Publication number: CN111836744B
Application number: CN201880091054.XA
Authority: CN
Inventors: P.C.隆布罗佐; J.斯威特克斯
Original assignee: Waymo LLC
Current assignee: Waymo LLC
Priority date: 2018-03-15
Filing date: 2018-12-17
Publication date: 2023-10-13
Anticipated expiration: 2038-12-17
Also published as: WO2019177676A1; US10675945B2; CN111836744A; US20190283533A1

Abstract

The present technology relates to condensate reduction systems for sensors. The system may include: a sensor cover 715, wherein the sensor cover is configured to house one or more sensor components; a flexible outer chamber 711; and conduits 760A, 760B. The outer chamber 711 may be communicably coupled to the interior of the sensor cover via conduits 760A, 760B, the conduits 760A, 760B being configured such that during an increase in pressure of the gas within the sensor cover 715, the gas flows to the outer chamber 711 via the conduits 760A, 760B, and during a decrease in pressure of the gas within the sensor cover, the gas flows from the outer chamber 711 to the sensor cover 715 via the conduits 760A, 760B.

Description

Condensate reduction system for a sensor

Cross Reference to Related Applications

The present application is a continuation of U.S. patent application Ser. No. 15/922,483, filed on even date 15 at 3/2018, the disclosure of which is incorporated herein by reference.

Technical Field

The present disclosure relates to condensate reduction systems for sensors.

Background

Various types of vehicles, such as automobiles, trucks, motorcycles, buses, boats, airplanes, helicopters, lawn mowers, recreational vehicles, amusement park vehicles, farm equipment, construction equipment, trolleys, golf carts, trains, carts, and the like, may be equipped with various types of sensors to detect objects in the environment of the vehicle. For example, a vehicle such as an autonomous vehicle may include a LIDAR, radar, sonar, camera, or other such imaging sensor that scans and records data from the environment of the vehicle. Sensor data from one or more of these sensors may be used to detect objects and their respective characteristics (location, shape, heading, speed, etc.).

However, these vehicles are often susceptible to environmental factors such as rain, snow, dust, condensate, etc., which may cause debris and contaminants to accumulate on the sensors. Typically, the sensor includes a cover to protect the internal sensor components of the sensor from debris and contaminants, but over time the cover itself can become dirty. In this way, the function of the internal sensor component may be hindered because the signals transmitted and received by the internal sensor component are blocked by debris and contaminants.

Disclosure of Invention

One aspect of the present disclosure provides a condensate reduction system for a sensor. The system comprises: a sensor cover, wherein the sensor cover is configured to house one or more sensor components; a flexible outer chamber; a catheter; wherein the outer chamber is communicably coupled to the interior of the sensor cover via a conduit configured such that during an increase in pressure of the gas within the sensor cover, the gas flows to the outer chamber via the conduit, and during a decrease in pressure of the gas within the sensor cover, the gas flows from the outer chamber to the sensor cover via the conduit.

In some examples, the system includes a cooling element positioned in line with the conduit between the sensor cover and the flexible outer chamber, wherein the cooling element cools the gas as it flows into and out of the outer chamber and condenses water vapor within the gas. In some cases, the system further includes an airlock configured to vent condensed water vapor from the condensate reduction system.

In some examples, the increase in pressure of the gas within the sensor cover is caused by an increase in temperature of the gas, and the decrease in pressure of the gas within the sensor cover is caused by a decrease in temperature of the gas. In some cases, the sensor cover is hermetically sealed. In some cases, the sensor cover includes one or more vent holes that form one or more openings between an interior of the sensor cover and an exterior of the sensor cover. The vent may comprise a gol vent.

In some cases, the external chamber is integrated into the sensor cover.

In some examples, the system further includes a nozzle configured to spray the directed fluid stream onto the sensor cover. In some cases, the system may include a pump for providing fluid to the nozzle. In some cases, the nozzle is connected to the pump via a second conduit. In some examples, the nozzle is located outside of the operating range of the sensor. In some cases, the system may further comprise a heater or heat source in fluid communication, wherein the heater or heat source heats the fluid.

In some cases, the system further includes a cooling element located within the sensor cover, wherein the cooling element cools the gas as it flows into and out of the external chamber and condenses water vapor within the gas.

In some cases, the system further comprises a monitoring sensor, wherein the monitoring sensor is configured to detect a build-up of one or more elements on the sensor cover. In some examples, the one or more elements are any combination of ice, snow, and condensate. In some cases, the monitoring sensor triggers the fluid removal system to provide a flow of fluid over the sensor cover upon detecting a build-up of one or more elements on the sensor cover.

In some cases, the system further comprises a motor for rotating the sensor cover, wherein the directed fluid stream is sprayed onto the sensor cover when the motor rotates the sensor cover.

In some cases, the system further comprises a motor for rotating the nozzle, wherein the directed fluid stream is ejected onto the sensor cover when the motor rotates the nozzle.

In some cases, the system further comprises a vehicle, wherein the condensate reduction system and the sensor are mounted to the vehicle.

Drawings

The present technology is illustrated by way of example, and not by way of limitation, in the figures of the accompanying drawings in which like reference numerals refer to similar elements and in which:

fig. 1 illustrates a sensor attached to a vehicle in accordance with aspects of the present disclosure.

Fig. 2 illustrates a sensor cover connected to a motor in accordance with aspects of the present disclosure.

FIG. 3 illustrates a nozzle directing fluid flow onto a sensor cap according to aspects of the present disclosure.

Fig. 4 is a schematic diagram of a sensor condensate prevention system according to the present disclosure.

Fig. 5 illustrates a nozzle directing fluid flow onto a sensor cap according to aspects of the present disclosure.

Fig. 6 illustrates a sensor cover with vent holes according to aspects of the present disclosure.

Fig. 7 illustrates an external volumetric system according to aspects of the present disclosure.

Fig. 8A and 8B are illustrations of a rotary door lock according to aspects of the present disclosure.

Fig. 9A and 9B are illustrations of a float valve according to aspects of the present disclosure.

Fig. 10 is an illustration of an interior view of a sensor cover in which a cooling element and an airlock are located, in accordance with aspects of the present disclosure.

Detailed Description

The present technology relates to removing or otherwise preventing condensation, ice, snow, and other such elements from accumulating on sensors, such as sensors external to a vehicle, in order to ensure proper operation. These sensors may include a cover to protect the internal sensor components from elements such as rain, snow, dust, and other such debris. However, the cover itself may be covered over time, such as by rain or ice during storms. Furthermore, the temperature difference between the inside of the sensor (i.e. inside the sensor cover) and the outside environment of the sensor (i.e. outside the sensor cover) may lead to condensate formation on the sensor cover. Thus, the function of the internal sensor components of the sensor may be hindered, as the signals sent and received by the internal sensor components may be blocked by the elements and/or condensate. However, by applying a fluid flow to the sensor cover and strategically managing the pressure, humidity, and/or temperature within the sensor cover, as described herein, problems with debris and condensate buildup inside and outside of the sensor cover may be minimized or eliminated.

As described above, the vehicle sensor may include an internal sensor component and a cover for accommodating the internal sensor component. The sensor cover may include a cover window configured at a specific location on the sensor cover. The internal sensor component may send and receive one or more signals through the cover window.

The sensor may be attached to the motor via a sensor shaft. In this regard, a first end of the sensor shaft may be attached to the first motor and an opposite end of the sensor shaft may be connected to the sensor and the sensor cover. The sensor cover, the sensor part and/or the entire sensor may also be rotated when the first motor rotates the sensor shaft. In some cases, the sensor may be stationary.

Elements deposited on a sensor cover including a sensor window may be removed by providing a temporary or continuous fluid flow. For example, the pump may force fluid through the conduit to a fixed or adjustable nozzle located around the sensor cover at a particular pressure. The nozzle may direct fluid toward the sensor cover to eject elements deposited on the sensor cover. In some cases, the fluid may be directed by the nozzle to a location on the sensor cover where the sensor captures sensor data, such as a sensor window, to allow the internal sensor components to send and receive signals through the window on the sensor cover unimpeded.

The fluid may be heated by a heater before being sprayed onto the sensor cover. In this regard, the heated fluid may be sprayed onto elements such as ice and/or snow on the sensor cover, causing the elements to be melted by the fluid and blown away.

Additional sensors may be used to monitor the sensor cover for accumulation of condensate or elements. The additional sensor may trigger the pump to push fluid through the nozzle when a predetermined accumulation threshold occurs. In case the additional sensor detects a condensate build-up or the possibility of a condensate build-up, the additional sensor may trigger the application of heated fluid to the sensor cover.

To absorb excess moisture within the sensor cover, a desiccant may be added to the interior of the sensor cover. In this regard, air and water vapor may permeate into the sensor cover through one or more vent holes or slits. The desiccant within the sensor cover may absorb water vapor and any condensed vapor to prevent condensation from building up on the sensor cover.

The sensor cover may be hermetically sealed to prevent air from exiting or entering the sensor cover. By preventing interaction of warm air inside the sensor cover and cooler air outside the sensor cover, condensate formation inside or outside the sensor cover can be avoided.

The external volume may be coupled to the sensor such that air may flow between the sensor cover, the external volume. The external volume may be flexible and may expand or contract in response to air entering or exiting based on pressure within the sensor cover. For example, as the temperature of the air within the sensor cover decreases, the air pressure within the sensor cover may decrease. This reduction in air pressure may cause air to travel from the external volume to the sensor cover, thereby minimizing the pressure differential between the environment outside the sensor and the interior of the sensor cover and the external volume. This may reduce the rate at which humid outside air enters the sensor cover.

The cooling element may be comprised between the sensor cover and the external volume, or within the sensor cover or the external volume. In this regard, air traveling between or within the sensor cover and/or the external volume may pass through the cooling element. The cooling element may cool the air as it passes therethrough, thereby condensing some or all of the water out of the air. To remove the condensate, an airlock may be used to pour the condensate out of the system or otherwise direct the condensate out of the system.

While certain aspects of the present disclosure are particularly useful in connection with certain types of vehicles, the vehicles may be any type of vehicle including, but not limited to, autonomous and semi-autonomous, as well as manually steered and/or operated automobiles, trucks, motorcycles, buses, boats, aircraft, helicopters, lawnmowers, recreational vehicles, amusement park vehicles, agricultural equipment, construction equipment, trolleys, golf carts, trains, and carts. Further, aspects of the present disclosure may be useful in connection with objects other than vehicles, such as wearable sensors, telephones, and other such objects that are susceptible to debris and contaminants.

The features described herein may allow for continued use of the sensor even when the cover, interior or exterior of the sensor becomes dirty or wet from the accumulation of debris, condensate, ice, and other such contaminants. By doing so, the sensor can continue to operate without being disturbed or without requiring an individual to manually replace the desiccant cartridge or clean the sensor cover. In this way, the sensor and the vehicle to which the sensor is mountable may be operated continuously in environments that generate large amounts of debris and contaminants, such as outdoors in rain or snow or in a construction site or off-road location. The features described herein may also reduce the risk of corrosion of the sensor components and electrical failure of the sensor components due to water buildup, and reduce stress-related stresses on the sensor cover. Furthermore, the features described herein may eliminate or reduce the need for the wiper to wipe debris and/or contaminants from the sensor cover, resulting in less moving parts for cleaning the sensor cover and reduced wear on the wiper blade and sensor cover. In this way, wiping noise and/or vibrations, such as those caused by the wiper blade rubbing against the sensor cover, may be reduced or avoided. Furthermore, the features described herein may remove stubborn contaminants from the sensor cover that the wiper may not be able to remove by melting and/or blowing away such contaminants.

The vehicle may have one or more sensors to detect objects external to the vehicle, such as other vehicles, obstacles on the road, traffic signals, signs, trees, etc. For example, the vehicle 101 as shown in fig. 1 may include lasers, sonar, radar, cameras, and/or any other detection device that captures images and records data that may be processed by a computing device within the vehicle. Sensors of the vehicle, such as LIDAR, radar, cameras, sonar, etc., may capture images and detect objects and their characteristics, such as position, orientation, size, shape, type, direction and speed of movement, etc. The image may include raw (i.e., unprocessed) data captured by the sensor and/or pictures and video captured by the camera sensor. The image may also include processed raw data. For example, raw data from sensors and/or the aforementioned features may be quantized or sorted into descriptive functions or vectors for processing by a computing device. The images may be analyzed to determine the position of the vehicle and detect and respond to objects as needed.

The sensor may be arranged around the outside or inside of the vehicle. For example, the housing 130, 140, 142, 150, 152 may include, for example, one or more LIDAR devices. The sensors may also be incorporated into typical vehicle components such as tail/turn signal lights 104 and/or rear view mirrors 108. In some cases, the laser, radar, sonar, camera(s), or other sensor may be mounted on a top plate attached to the base 120 (such as in the housing 122).

The vehicle sensor may include an interior sensor component, a cover for receiving the interior sensor component, and a cover window. The cover window may be configured at a particular location on the sensor cover, and the internal sensor component may transmit and receive one or more signals through the cover window. The sensor cover may be configured in various shapes and sizes, such as spheres, cylinders, cuboids, cones, prisms, pyramids, cubes, and the like. For example, as shown in fig. 2, the sensor cover 215 of the sensor 201 may be configured such that it has a dome-shaped portion 217, the dome-shaped portion 217 having a frustoconical sidewall 205. The sensor cover 215 may be composed of materials such as plastic, glass, polycarbonate, polystyrene, acrylic, polyester, and the like.

As described above, the cover may include a cover window through which the internal sensor component may transmit and receive signals. For example, as further shown in fig. 2, the sidewall 205 of the sensor cover 215 may include a cover window 216 (also referred to as a sensor window 216) incorporated therein to allow a signal (not shown) to penetrate the sensor cover 215. Although the lid window 216 is shown as only a portion of the side wall 205, in some cases, the entire side wall 205 may be configured as a lid window. Further, a plurality of cover windows may be located on the sensor cover 215. The cover window 216 may be composed of the same or different material as the sensor cover 215. In some cases, the entire sensor cover 215 or a majority of the sensor cover may be penetrable by signals transmitted and received by the internal sensor components, allowing the entire sensor cover 215 to function as a cover window.

The sensor may be attached to the motor via a sensor shaft. For example, as further shown in fig. 2, the sensor shaft 230 may include a first end 232 and a second end 234. A first end 232 of the sensor shaft 230 may be attached to the sensor motor 220 and a second end 234 of the sensor shaft 230 opposite the first end 232 may be connected to the sensor 201 and the sensor cover 215. In this regard, the first end 232 of the sensor shaft 230 may be attached to the motor 220 via a belt, gear, chain, friction roller, or the like. The motor 220 may rotate the sensor shaft 230 in the first direction 235, causing the entire sensor 201 to also rotate in the first direction 235. In some embodiments, the sensor shaft 230 may simply rotate the sensor cover 215. The sensor 201 and motor 220 may each be located inside or outside the vehicle.

Elements deposited on the sensor cover may be removed by providing a temporary or continuous fluid flow. For example, as the vehicle progresses during travel, such as during snowing and/or ice storms, contaminants 330, which may represent snow and ice, or other such elements, may accumulate on the sensor cover 215 of the sensor 201, as shown in fig. 3. A nozzle 310 (such as a spray nozzle) located near the sensor cover 215 may provide a directed fluid flow 320 to spray and/or melt away the contaminant 330 as the contaminant 330 affects the operation of the internal components of the sensor, as further shown in fig. 3. The fluid may be any type of liquid, such as water, antifreeze, detergent, gas and/or soap.

The nozzle may be part of a fluid removal system that may include a pump to force fluid through the nozzle. For example, the fluid removal system 400 as shown in fig. 4 may include a pump 455 and a nozzle 310. The pump and nozzle may be connected together via one or more conduits 460A-B. The one or more conduits may be rubber, plastic, metal, or other such tubing that enables fluid flow into and out of components of the fluid removal system. Although three conduits 460A-C are shown in FIG. 4, fewer or more conduits may be present in the fluid removal system. In this regard, the number of conduits may be based on the number of devices within the fluid removal system 400 and the number of connections required between those devices. For example, as the number of nozzles increases, the number of conduits from pump 455 and/or heater 430 may increase, as discussed herein. In addition, the fluid removal system may include more than one pump and heater, resulting in the need for additional conduits.

The fluid removal system 400 includes a fluid source 450. In this regard, the fluid source 450 may be a plastic reservoir or other such reservoir that stores the fluid output by the nozzle 310. For example, and as shown in fig. 4, pump 455 may be connected to fluid source 450 via conduit 460C. In some cases, pump 455 may be located within fluid source 450. When the fluid removal system 400 is operated, such as by control of the controller 480, the pump 455 may cause fluid to travel from the fluid source 450 to the nozzle 310 via the conduits 460A-C at a particular pressure.

The nozzle may apply a directed fluid flow to the sensor cover at a particular rate. In this regard, referring to both fig. 3 and 4, the rate of the directed fluid flow 320 output by the nozzle 310 may be controlled and adjusted based on the pressure of the fluid generated by the pump 455 and the flow rate of the nozzle 310. In this regard, the flow rate of the nozzle 310 and the pressure generated by the pump 455 may be increased and/or decreased to produce a particular rate of the directed fluid flow 320. In some cases, the directed fluid flow may have a velocity of about 8 meters per second or greater or less as measured from about 25mm or greater or less from the nozzle surface to clean a sensor cover, such as sensor cover 215, from about 4mm or greater or less from the nozzle surface.

The nozzle may apply a directed fluid flow in a particular direction. In this regard, the direction of the nozzle 310 may be fixed or adjustable and may be set such that it ejects a directed fluid stream onto a particular area of the sensor cover. In some cases, the direction of the nozzle may be manually adjusted such that the nozzle may spray a directed fluid stream over more than one area of the sensor cover. In some cases, the direction of the nozzle 310 may be controlled by the motor 340 such that the direction of the nozzle may be automatically directed to a particular location of the sensor cover, for example, in response to instructions from the controller 480.

In some cases, the angle of the directed fluid flow relative to the sensor cover may be adjusted based on the direction of the nozzle and the rate of the directed fluid flow. In this regard, the directed fluid flow 320 may contact the sensor cover 215 at a particular angle, thereby forcibly moving elements on the sensor cover, such as contaminants 330, in a particular direction. For example, the directed fluid flow 320 may contact the sensor cover such that the contaminants 330 are directed upward and away from the sensor window 216.

Although only a single nozzle is shown in fig. 3 and 4, more than one nozzle may be used. In this regard, more than one nozzle 310 may be located around the sensor 201 such that the nozzle may eject all or a portion of the sensor cover 215. In some cases, more than one nozzle may spray the same area of the sensor cover 215. Although fig. 3 shows the nozzle 310 as being at the bottom of the sensor 201, the nozzle 310 may be located above the sensor 201 or adjacent to the sensor 201. In some cases, the nozzle may be located outside of the operating range of the one or more sensors.

In some cases, the sensor cover may be rotated while the one or more nozzles apply a directed fluid flow. For example, as shown in fig. 3, the sensor cap 215 may be rotated in the first direction 235 while the nozzle 310 sprays the directed fluid stream 320 at the sensor cap 215. By doing so, the directed fluid flow 320 may contact an entire perimeter portion or area of the sensor cover 215, such as the entirety of the sensor window 216 or some other portion of the sensor cover.

The heater may be used to heat the fluid as it travels from the pump to the nozzle before it is sprayed onto the sensor. For example, referring again to the fluid removal system of fig. 4, a heater 430 may be located between the pump 455 and the nozzle 310. The heater 430 may heat the fluid as it travels from the pump 455 through conduit 460B through conduit 460A to the nozzle 310. When output by the nozzle 310, the heated fluid may be sprayed onto elements on the sensor cover 215, such as the contaminants 330, causing debris and contaminants to be melted by the fluid and blown away. In some cases, a cooler (not shown) may be used in addition to heater 430 or in place of heater 430 to cool the pressurized fluid prior to output by the nozzle. The heater 430 may be directly connected to a fluid source to heat the contents of the fluid source, such as a fluid. In some cases, the heater may be powered alone or utilize waste heat from other components of the vehicle (such as the drive train or electronics cooling circuit). To heat or assist the heater in heating the fluid within the fluid source 450, the fluid source 450 may be located in a warm portion of the vehicle, such as within the cabin, or proximate a heat source, such as a drive train or electronics cooling circuit.

In some cases, heated fluid may be provided to the sensor cover to prevent or eliminate condensate buildup. In this regard, the application of a temporary or continuous flow of heated fluid to the sensor cover 215 may raise the temperature of the sensor cover, thereby preventing the formation of condensate. Heating of the sensor cover 215 may also cause any condensate on the sensor cover to evaporate more quickly. For example, fig. 5 shows condensate 530 that has accumulated on the sensor window 216 in the sensor cover 215 that is coupled to the sensor 201. The heated directed fluid flow 253 may be sprayed onto the portion of the sensor window 216 where condensate 530 has accumulated. By doing so, the sensor window 216 may be warmed, thereby preventing the formation of additional condensate. Additionally, the heated directed fluid flow may spray away the accumulated condensate 530 and/or cause the accumulated condensate 530 to quickly evaporate. In addition, heat added to the outer surface of the sensor cover may be conducted through the sensor cover, heating the inner surface of the sensor cover, causing condensate to evaporate from the inner surface of the sensor cover.

In some cases, the directed fluid flow may be provided to a location on the sensor cover through which the sensor captures sensor data, such as images, light, and the like. As discussed herein, the internal sensor component may send and receive signals through a sensor window, such as sensor window 216 on sensor cover 215. Thus, as long as the sensor window 216 remains free of buildup, the internal sensor components can continue to capture sensor data without being disturbed by elements or condensate. Thus, the heated and/or unheated directed fluid flow may be applied only to the sensor window 216 and/or the area surrounding the sensor window 216 to prevent condensate or elements from building up on the sensor window 216.

In some examples, additional sensors may be used to automatically determine when fluid is applied to the sensor cap and whether the fluid should be heated. In this regard, additional sensors, such as one or more humidity sensors or cameras located inside the sensor cover 215 or adjacent to the outside of the sensor cover 215, may be used to monitor the sensor cover for accumulation of condensate or elements. The additional sensor may trigger the application of fluid to the sensor cap when a predetermined accumulation threshold occurs. For example, the sensor 550 of fig. 5 (which may also be referred to as a monitoring sensor 550) may monitor the accumulation of condensate or elements near the sensor 201 or on the sensor 201. When the accumulation of condensate or elements reaches a predetermined accumulation threshold, the sensor 550 may trigger the controller 480 to operate the fluid removal system 400 and apply fluid to the sensor cap 215. For example, based on the set of images, one or more camera sensors may determine occlusion of a portion of the sensor cover over time because of a blockage within the image or a decrease in image sharpness may increase. In some cases, different sensors observing the same scene may be compared to find a significant difference that would indicate a problem with one of the sensor views. For example, a lidar sensor may detect sudden and persistent changes in return signal strength and timing over an area of a scene. Depending on the configuration of the lidar, this may be a point of change or a band of change depending on whether the window rotates with the sensor. A rotating lidar looking at the scene through multiple windows over alternating periods of time may observe scene data differences between one window and another window, indicating a pile-up in which the intensity is reduced.

The additional sensor may also monitor the moisture content and temperature in and around the sensor to determine if condensate may form. Upon determining that condensate may form, an additional sensor may trigger the application of heated fluid to the sensor cover. In some cases, the sensor itself or an additional sensor may initiate the application of fluid to the sensor cover upon determining that the signal of the internal component is blocked.

Referring back to fig. 4, the fluid removal system 400 may include a controller 480, such as one or more microprocessors, processors, computer devices, or the like, that may control the operation of the components of the fluid removal system. In this regard, the controller 480 may be connected to the pump 455 and the heater, as well as other components of the system, such as additional sensors described herein, such as the sensor 550 monitoring the sensor cover 215. Upon receiving a signal to engage or determining that the system should engage based on data received from additional sensors, such as monitoring sensor 550, controller 480 may trigger one or more components of fluid removal system 400 to engage. For example, upon determining that a sensor cap (such as sensor cap 215) is covered by condensate or other element, controller 480 may trigger pump 455 to engage, causing nozzle 310 to output a fluid flow on the sensor cap. The controller may disengage the components of the fluid removal system 400 when dirt and debris is removed from the sensor cover. In some cases, the controller may receive temperature and humidity data from within the sensor cover and from outside the vehicle to determine whether the heater 430 should engage or disengage during operation of the fluid removal system. In this regard, if the ambient temperature is below a threshold, such as 40 degrees Fahrenheit or higher or lower, the controller may trigger the heater to engage when the pump 420 engages.

In some cases, the controller may receive signals from manual operation inputs such as switches, buttons, levers, and the like. In response to the received signal, the controller 480 may engage or disengage the fluid removal system 400.

As discussed herein, air or other such gases inside the sensor may be heated and retain additional moisture during operation of the sensor. Cooler air at or near the exterior of the sensor cover may interact with and cool the warmer interior air, resulting in condensation build-up at the interior and/or exterior of the sensor cover. A desiccant may be added to the sensor interior to absorb water vapor. For example, as shown in fig. 6, a sensor 601 comparable to the sensor 201 may include one or more vent holes 610, such as golr vent holes. The one or more vents 610 may allow outside air and water vapor to permeate into the interior of the sensor, as indicated by arrows 615. To prevent condensation of water vapor, one or more desiccants, such as desiccant cartridge 620, may be added to the sensor interior, as further shown in fig. 6. The desiccant cartridge can absorb water vapor and any condensed vapor to prevent condensation from building up on the sensor cover. The desiccant can be replaced when it becomes saturated.

Alternatively, the sensor cover may be hermetically sealed to prevent the introduction of humid outside air, thereby preventing the formation of condensate. However, during operation of the sensor, temperature fluctuations may change the pressure within the sensor relative to the environment external to the sensor, thereby creating a vacuum. The pressure differential may provide a driving force to promote the natural pore flow of moisture and still water through the crevices, seals, and plastic and other materials of the housing. The pressure differential may also damage the sensor cover and/or the internal sensor components. In addition, in the case where the sensor cover is damaged, outside air and water vapor may be sucked into the sensor through the damaged portion, possibly resulting in the formation of condensate.

To prevent damage to the sensor cover and/or the internal sensor components, a flexible external volume may be connected to the inside of the sensor cover. In this regard, the external volume may expand or contract in response to pressure fluctuations within the sensor cover, thereby maintaining a relatively stable pressure within the sensor cover. For example, as shown in the external volume system 700 of fig. 7, a flexible external volume 711 (such as a flexible chamber, compartment, container, bellows, bag, collapsible bottle, etc.) may be connected to the interior of the sensor cover 715 of the sensor 701 comparable to the sensors 201 and 601. The flexible exterior volume may be connected to the interior of the sensor cover via one or more conduits, such as conduits 760A and 760B, as further shown in fig. 7. The conduit may be a flexible or rigid tube connected at one end to the inside of the sensor cover and at the other end to a flexible external volume. The conduit may be capable of allowing air to pass from one component of the external volume system 700. In some cases, the external volume 711 and conduit may be flexible panels on the sensor cover that are allowed to deform with pressure changes. For example, the external volume may be a rubber diaphragm, bellows, or other such structure configured as a wall, top, or bottom of the sensor cover, and the conduit may be a path between the external volume and the interior of the sensor cover.

As the temperature inside the sensor cover increases, the air pressure inside the sensor cover 715 may increase as the air expands due to the increased heat. The increased air pressure may force air through the conduit into the flexible outer volume 711, causing the flexible outer volume to expand. As the temperature inside the sensor cover 715 decreases, the gas pressure inside the sensor cover 715 may decrease, causing the gas in the flexible outer volume 711 to flow back into the sensor cover 715. In this way, pressure fluctuations within the sensor cover 701 may be minimized, thereby avoiding damage to the sensor cover. A temperature sensor (not shown) inside the sensor cover 715 may monitor the inside temperature of the sensor cover.

In some cases, the flexible external volume may be connected to the interior of a non-hermetically sealed sensor (such as sensor 601 containing a vent hole, such as golr vent hole 610 or a leak path through the seal and material aperture). In this case, the flexible outer volume 711 minimizes the pressure difference between the external environment and the environment inside the sensor cover and the outer volume. By doing so, the flexible outer volume 711 may reduce the flow of ambient water vapor into the sensor, thereby minimizing the chance of condensate forming on the sensor cover.

In some cases, a cooling element may be added between the sensor cover and the external volume of the external volume system 700. In this regard, as the gas travels between the sensor cover 715 and the flexible outer volume 711, it may pass over a cooling element 702, such as a condenser, as further shown in fig. 7. The cooling element 702 may be configured such that it is cool enough to condense some or all of the water vapor out of the air as it passes through the conduit. By doing so, the dew point of the total gas volume is reduced.

The condensed water may be poured from the cooling element 702 through an airlock 704 as further shown in fig. 7. In this regard, the cooling element 702 may include an airlock 704 or be connected to an airlock via a conduit such as 760C. The airlock may prevent air from entering the conduit and/or the external volume system 700 while allowing condensed water to exit the system. For example, as the cooling element 702 condenses the water vapor, the water vapor may collect at the airlock 704. The airlock 704 may then pour the condensed water from the external volume system 700.

The airlock may be any type of airlock capable of passing liquid while preventing air transmission, such as a p-type trap, a p-type trap with sealing liquid, a revolving door, a float valve, and the like. For example, the airlock may be a revolving door 801 as shown in fig. 8A and 8B. The rotary door airlock may include a collection chamber 810 in which condensate 802 may be collected. When a predetermined amount of condensed water 802 is collected in the collection chamber 810, the rotation door 801 may be rotated in a first direction 830, as shown in fig. 8A. Upon rotation, the collection chamber 810 of the turnstile 801 may be inverted such that condensate is dumped from the collection chamber 810 to a location outside of the external volumetric system 700, as shown in fig. 8B.

The airlock may alternatively be a float valve as shown in fig. 9A and 9B. Float valve 901 may include a weight 902, a plug 910, and a float 904, as shown in fig. 9A. The weight 902 of the float valve may force the plug 910 to slide into the gap 911 of the float valve. As condensate 920 builds up in the float valve 901, the float 904 may begin to rise. When sufficient condensate 920 collects in the float valve 901, the float may raise the plug 910 out of the gap 911, thereby allowing the condensate 920 to pass through the gap 911, as shown in fig. 9B. When condensate is drained from float valve 901, weight 902 may direct plug 910 back into the gap, sealing the gap once a predetermined amount of condensate is released. Float valves may also be opened and closed using an electric motor, solenoid, or other element.

In some cases, the cooling element 702 may be located within a sensor cover 715 of the sensor 701, as shown in fig. 10. In this regard, some or all of the gas flowing into the sensor cover may be cooled and water may be condensed out. All of the condensed water may then pass through the airlock 704 to be removed from the interior of the sensor cover 715.

Most of the foregoing alternative examples are not mutually exclusive, but may be implemented in various combinations to achieve unique advantages. As these and other variations and combinations of the features discussed above can be utilized without departing from the subject matter defined by the claims, the foregoing description of the embodiments should be taken by way of illustration rather than by way of limitation of the subject matter defined by the claims. By way of example, the foregoing operations need not be performed in the exact order described above. Rather, the various steps may be processed in a different order, such as upside down or simultaneously. Unless otherwise indicated, steps may also be omitted. Moreover, the provision of examples described herein and phrases such as "including," "comprising," and the like should not be construed as limiting the claimed subject matter to particular examples; rather, the examples are intended to illustrate only one of many possible embodiments. Furthermore, the same reference numbers in different drawings may identify the same or similar elements.

Claims

1. A condensate reduction system for a sensor, the system comprising:

a sensor cover, wherein the sensor cover is configured to house one or more sensor components;

a flexible outer chamber;

a conduit; and

a cooling element located between the sensor cover and the flexible outer chamber,

wherein the external chamber is communicably coupled to the interior of the sensor cover via the conduit,

wherein the flexible outer chamber deforms in response to a pressure change within the sensor cover such that during an increase in pressure of the gas within the sensor cover, gas flows to the outer chamber via the conduit, and during a decrease in pressure of the gas within the sensor cover, gas flows from the outer chamber to the sensor cover via the conduit,

wherein the cooling element is located in the extended path of the conduit to cool the gas as it flows into and out of the external chamber via the conduit and to condense water vapour within the gas.

2. The system of claim 1, wherein the increase in pressure of the gas within the sensor cover is caused by an increase in temperature of the gas and the decrease in pressure of the gas within the sensor cover is caused by a decrease in temperature of the gas.

3. The system of claim 1, wherein the cooling element is positioned in-line with the conduit.

4. The system of claim 3, wherein the system further comprises an airlock configured to vent condensed water vapor from the condensate abatement system.

5. The system of claim 1, wherein the sensor cover is hermetically sealed.

6. The system of claim 1, wherein the sensor cover comprises one or more vent holes that form one or more openings between an interior of the sensor cover and an exterior of the sensor cover.

7. The system of claim 1, wherein an external chamber is integrated into the sensor cover.

8. The system of claim 1, further comprising a nozzle configured to spray a directed fluid stream onto the sensor cover.

9. The system of claim 8, further comprising a pump for providing fluid to the nozzle.

10. The system of claim 9, wherein the nozzle is connected to the pump via a second conduit.

11. The system of claim 9, further comprising a heater or heat source in communication with the fluid, wherein the heater or heat source heats the fluid.

12. The system of claim 9, wherein the nozzle is located outside of an operating range of the sensor.

13. The system of claim 1, further comprising:

a cooling element located within the sensor cover, wherein the cooling element cools the gas as it flows into and out of the external chamber and condenses water vapor within the gas.

14. The system of claim 1, further comprising a monitoring sensor, wherein the monitoring sensor is configured to detect a buildup of one or more elements on the sensor cover.

15. The system of claim 14, wherein the one or more elements are any combination of ice, snow, and condensate.

16. The system of claim 14, wherein the monitoring sensor, upon detecting a buildup of one or more elements on the sensor cover, triggers a fluid removal system to provide a fluid flow on the sensor cover.

17. The system of claim 8, further comprising a motor for rotating the sensor cover, wherein the directed fluid flow is sprayed onto the sensor cover as the motor rotates the sensor cover.

18. The system of claim 8, further comprising a motor for rotating the nozzle, wherein the directed fluid flow is sprayed onto the sensor cover as the motor rotates the nozzle.

19. The system of claim 1, further comprising a vehicle.

20. The system of claim 19, wherein the condensate reducing system and sensor are mounted to the vehicle.